A system, such as a website, that allows users to interact with the system typically stores a record for each users of the system. These records may comprise information provided by the user as well as information gathered by the system related to activities or actions of the user on the system. For example, a system may require a user to enter information such as contact information, gender, preferences, interests, and the like in an initial interaction with the system, which is stored in the user's record. A user's activities on the system, such as frequency of access to particular information on the system, also provide information that can be stored in the user's record. The system may then use information provided by the user and information gathered about the user, to constantly customize interactions of the system with the user. For example, a website selling books may keep track of a users previous purchases and provide the user with information on related books during subsequent interactions with the system. Information in a user's profile may also be used by the system to target advertisements that are of interest to the user. Using information collected from and about users results in a system that is more efficient and beneficial for both the user and the system.
However, prior systems, including websites, lack the ability to use information associated with a user's social connections or activities to customize and/or personalize the user's experience while using the system. Access to information about the user's social interactions and/or the activities of a user's social connections (e.g. friends, family, co-workers, etc.) improves the user's experience while using the system and increases the chance that the user will use the system in the future. For example, users visiting a website that sells books may be interested in books that their social connections have looked at, book reviews or comments provided by their social connections, and other social information that might inform their purchases of book from the website. The system itself also benefits, because it can leverage information about the user and the user's social connections to more accurately determine what a user might be interested in. Such a system can use social information to customize a user's experience and target products, services and/or advertisements to the user.
Typical systems do not possess sufficient information about a user's social connections to customize the user's experience or effectively target advertising to the user. Assembling enough information about a user's social connections for these purposes requires a system to interact with a large number of users over an extended period of time. The majority of websites will not have the resources, expertise, or user base required to build and maintain a system of the scale necessary to capture, organize and maintain a sufficient amount of information about users' social connections and their activities. Thus, users of these systems will have an inferior experience, and the customization/personalization provided by these sites is unlikely to accurately take into account or reflect information about the user's social connections and their activities.
A social networking system may establish privacy settings to allow users to decide who can access information associated with the user within the social networking system. Existing social networking systems enforce these privacy settings to control how information is used within the social networking system, but do not provide for enforcement of privacy settings outside the social networking system. A user who is not allowed to access particular information associated with another user within the social networking system should not be allowed to see the same information outside of the social networking system. When social network information is made available to external systems outside the social networking service, there are no existing techniques for enforcing the privacy settings established within the social networking service, outside that system on external systems. This is an even more difficult problem to resolve where privacy settings on the social networking system may be changed over time.